Polyarylene ether has excellent heat resistance and can be blended with a thermoplastic resin composition containing an aromatic vinyl resin to impart heat resistance thereto.
Polyarylene ether can be prepared using a combination of manganese salt and an amine compound as a catalyst in the presence of oxygen. Manganese salt does not decline in catalytic activity due to water generated in the polymerization. Manganese salt, however, can impart a color and can decrease thermal stability if it remains in the polymerized polyarylene ether.
Polyarylene ether can also be produced using a combination of copper salt and an amine compound as a catalyst. One such method uses acetonitrile, chloroform, toluene, benzene, pyridine, ethylbenzene, cyclohexane, xylene, chlorobenzene, nitrobenzene, 1,2-dichlorobenzene, or water as a solvent. Toluene or chloroform is generally used.
However, when toluene is used as a solvent, a violent reaction occurs in the initial stage of polymerization, making it difficult to adjust heat of polymerization. It is also difficult to deal with toluene due to the low flash point of toluene. Further, if water is generated during polymerization, a water layer is separated due to low solubility of water and a copper-amine catalyst transfers to the separated water layer, thereby reducing catalytic activity and resulting in a longer polymerization time and a lower yield. In order to solve these problems, a desiccant (MgSO4) is used to remove generated water, surfactants are added, or an amphiprotic solvent such as alcohol is added to prevent the decline in catalytic activity.
The use of chloroform as a solvent can be dangerous and environmentally undesirable. Further, chloroform can generate a large amount of byproducts such as diphenyl quinone, as compared with aromatic solvents (such as benzene and toluene, among others).
Thus, there is a need for a new method for preparing polyarylene ether, which does not harm humans, provides stability in treatment and reaction, and does not decrease catalytic activity.